Validating radio frequency identification (rfid) alarm event tags

ABSTRACT

An RFID portal of an EAS system first interrogates a first zone extending into a controlled area beyond a threshold distance from an interrogating antenna of the portal. The portal defines an exit from the controlled area, the threshold distance being less than a width of the exit. The portal first detects, in response to the first interrogating, a first response of a particular RFID tag. The portal second interrogate, subsequent to the first detecting, in a second zone extending into the controlled area at least to the threshold distance. The portal second detects, in response to the second interrogating, at least one second response of the particular RFID tag indicating a received signal strength of the second interrogating at the particular RFID tag corresponding to a distance from an interrogating antenna of the portal less than the threshold distance. The EAS system alarms in response to the second detecting.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/036,635, entitled “Validating Radio Frequency (RFID) Alarm EventTags,” filed Sep. 29, 2020; which claims the benefit of U.S. ProvisionalPatent Application No. 62/908,536, entitled “System and Method ImprovedTheft Determination for RFID Exit Portal Alarms with Customer InterceptDirective,” filed Sep. 30, 2019, which is expressly incorporated byreference herein in its entirety.

BACKGROUND Technical Field

The present disclosure relates generally to Electronic ArticleSurveillance (EAS). Examples related to EAS using a Radio FrequencyIdentification (RFID) tag.

INTRODUCTION

Electronic article surveillance (EAS) systems are used to controlinventory and to prevent or deter theft or unauthorized removal ofarticles from a controlled area. Such systems establish anelectromagnetic field or “interrogation zone” that defines asurveillance zone (for example, entrances and/or exits in retail stores)encompassing the controlled area. The articles to be protected aretagged with an EAS security tag. Tags are designed to interact with thefield in the interrogation zone. e.g., established by an EAS portal. TheEAS portal includes one or more EAS readers (e.g., transmitter/receiver,antennas), and an EAS detection module/controller. The presence of a tagin the interrogation zone is detected by the system and appropriateaction is taken. In most cases, the appropriate action includes theactivation of an alarm.

In the retail industry, it is common to “source tag” articles with RFIDtags, either at the time of packaging/manufacture, or at some otherpoint in the in the supply chain. At the same time, EAS technology anddevices have proven critical to the reduction of theft and so called“shrinkage.” Since many articles arrive at the retailer with RFID tags,it is desirable that RFID tag be used also to provide EAS functionalityin addition to their intended function of providing capabilities such asinventory control, shelf reading, non-line of sight reading, etc.

In some implementations, an RFID tag can be used to simulate EASfunctionality by sending special codes when a reader interrogates theRFID tag. This arrangement advantageously eliminates the need for aseparate EAS component, such an acousto-magnetic (AM) component, withinthe tag, or a separate EAS tag. Various schemes can be used to enablethe use of RFID tags to simulate EAS functionality. In some suchsystems, the RFID tag indicates in some way that the item to which thetag is attached has been purchased at point of sale (POS). If the RFIDtag is a detachable tag, the RFID tag can be simply detached at thepoint of sale. In such a system, the RFID readers at the exit wouldtrigger an alarm if any tags are detected. In some such systems, data iswritten to the RFID chip at the POS to confirm the item was purchased.One common method is encoding a bit-flip at the POS, with the changedbit indicating that the item is authorized for removal. Other systemsmay read a unique ID from the tag, and store the unique ID in theenterprise system when the tagged item is purchased, so that thepurchase can be verified by RFID readers as the tag exits the premises.If the purchase of the item cannot be verified based on tag data whenthe tag passes out of the store, an alarm can be triggered.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects and is intended toneither identify key or critical elements of all aspects nor delineatethe scope of any or all aspects. Its sole purpose is to present someconcepts of one or more aspects in a simplified form as a prelude to themore detailed description that is presented later.

Examples of the technology disclosed herein include methods, systems,and apparatuses of electronic article surveillance (EAS). In someexamples, an RFID portal of an EAS system first interrogates in a firstzone extending into a controlled area beyond a threshold distance froman interrogating antenna of the RFID portal. The RFID portal defines anexit from the controlled area, the threshold distance being less than awidth of the exit. The RFID portal first detects, in response to thefirst interrogating, a first response of a particular RFID tag. The RFIDportal second interrogate, subsequent to the first detecting, in asecond zone extending into the controlled area at least to the thresholddistance. The RFID portal second detects, in response to the secondinterrogating, at least one second response of the particular RFID tagindicating a received signal strength of the second interrogating at theparticular RFID tag corresponding to a distance from an interrogatingantenna of the RFID portal less than the threshold distance. The EASsystem alarms in response to the second detecting.

In some examples, first detecting includes determining, by the EASsystem, that the particular tag is moving in a direction exiting thecontrolled area. In such examples, second interrogating is in responseto the first detecting. In some examples, alarming includes displayinginformation relating to at least one of: the particular RFID tag, and anarticle associated with the particular RFID tag. In some such examples,displaying includes displaying on one of the RFID portal or a mobilecommunication device.

In some examples, indicating a received signal strength comprisesresponding with a received signal strength indicator (RSSI). In someexamples, the threshold distance is no greater than one foot, in othersthe threshold distance is no greater than two feet. In some examples,the EAS system receives, prior to the first interrogating, selection ofthe threshold distance. In some examples, the first interrogating ismulti-session interrogating during which the particular RFID tag wouldnot be guaranteed to respond to a subsequent interrogation.

In such examples, the second interrogating includes interrogating inwhich all RFID tags within the threshold distance are allowed torespond. In some examples, the second detecting includes at least apredetermined threshold number, greater than one, of second responses.In some examples, the alarming further requires an indication of atleast one person in the exit concurrent with the first detecting.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an illustrative architecture for a system.

FIG. 2 is an illustration of an illustrative architecture for a tag.

FIG. 3 is an illustration of an illustrative architecture for a tagreader.

FIG. 4 is an illustration of an illustrative architecture for a server.

FIG. 5 is a plan view of an EAS portal at a choke point.

FIG. 6 is a top view of the EAS portal in FIG. 5 .

FIG. 7 is a representation of an illustrative architecture surroundingan EAS portal.

FIG. 8 is a flow chart flow chart of a method of electronic articlesurveillance, in accordance with examples of the technology disclosedherein.

FIG. 9 is an illustration of a computing device including components forperforming the function of examples of the technology disclosed herein.

DETAILED DESCRIPTION

It will be readily understood that the components of the embodiments asgenerally described herein and illustrated in the appended figures couldbe arranged and designed in a wide variety of different configurations.Thus, the following more detailed description of various embodiments, asrepresented in the figures, is not intended to limit the scope of thepresent disclosure, but is merely representative of various embodiments.While the various aspects of the embodiments are presented in drawings,the drawings are not necessarily drawn to scale unless specificallyindicated.

The present solution may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the present solution is indicated bythe appended claims rather than by this detailed description. Allchanges that come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

Reference throughout this specification to features, advantages, orsimilar language does not imply that all of the features and advantagesthat may be realized with the present solution should be or are in anysingle embodiment of the present solution. Rather, language referring tothe features and advantages is understood to mean that a specificfeature, advantage, or characteristic described in connection with anembodiment is included in at least one embodiment of the presentsolution. Thus, discussions of the features and advantages, and similarlanguage, throughout the specification may, but do not necessarily,refer to the same embodiment.

Furthermore, the described features, advantages, and characteristics ofthe present solution may be combined in any suitable manner in one ormore embodiments. One skilled in the relevant art will recognize, inlight of the description herein, that the present solution can bepracticed without one or more of the specific features or advantages ofa particular embodiment. In other instances, additional features andadvantages may be recognized in certain embodiments that may not bepresent in all embodiments of the present solution.

Reference throughout this specification to “one embodiment,” “anembodiment,” or similar language means that a particular feature,structure, or characteristic described in connection with the indicatedembodiment is included in at least one embodiment of the presentsolution. Thus, the phrases “in one embodiment”, “in an embodiment,” andsimilar language throughout this specification may, but do notnecessarily, all refer to the same embodiment.

As used in this document, the singular form “a,” “an,” and “the” includeplural references unless the context clearly dictates otherwise. Unlessdefined otherwise, all technical and scientific terms used herein havethe same meanings as commonly understood by one of ordinary skill in theart. As used in this document, the term “comprising” means “including,but not limited to.”

Currently, using RFID as an EAS exit solution is limited by stray orreflected alarms when transmission powers are increased. People walkingthrough the EAS portal may trigger alarms even if they are not removingarticles from the premises without authorization. Alarms can be causedby stationary RFID tags located some distance from the exit. Further,such an approach limits the ability for the retailer to place articlestoo close to an EAS portal due to false alarms. The large read ranges ofthe RFID technology coupled with RF reflections makes it very difficultto control the RFID system's detection area at the exit from thecontrolled area.

In real-world environments, with changing RF reflections may be subjectto constant change to store fixtures, furniture, support columns, doors,customers in motion, shopping carts etc. These types of systemssometimes have a hard time properly discriminating between actual tagsthat are read outside (or detected going outside), and tags on itemsproperly inside the store that are falsely read outside due to RFreflections, multipath/backscattering, or missed inventory attempts dueto temporary interferers.

As RFID transmission levels are increased in a RFID-as-EAS system, thenumber of false alarms caused by stray or reflected may also increase,which can compromise the accuracy and effectiveness of the system. Withincreased transmission power levels, people walking through the EASportal may appear to be triggering alarms, even if they are not tryingto remove articles from the premises without authorization. These falsealarms can be triggered by stationary RFID tags located some distancefrom the exit, not the person exiting the store.

Further, there are situations in which human judgment is useful todetermine if an RFID-as-EAS alarm is indicative of theft, or if thealarms is simply a false alarm. Typically, a retail store will station ahuman guard or monitor at the point of exit to interact with customersexiting the store, and this the human guard or monitor is tasked withproviding the last line of defense against theft. If there is an alarmcaused by detection of an unauthorized RFID tag, the guard must quicklydetermine what articles may have been stolen, and by which people. Thiscan be difficult in crowded, fast-moving situations.

Typically, the guard/monitor takes into account that there may be a caseof a false alarm as can occur when the detected tag is on an articleinside the store and there is no actual theft. In this case, the retailstore would not want a guard to detain unfairly a customer who hasproperly purchased their article in an attempt to determine if they havestolen the article.

Another challenge for the guard or monitor is when multiple people arenear the exit gate. If more than one customer is traveling through ornear the exit gate and an alarm is triggered, the guard or monitortypically attempts to determine, quickly and accurately, whichcustomer/person could be stealing an article. In order to help theguard, make this decision it would be useful for the EAS system tosupply more information than just sounding the alarm, preferablycommunicating to the guard or monitor in close to real time.

Examples of the technology disclosed herein can provide for the nearreal-time collection/display of additional data that is related to thedetection of an unauthorized RFID tag moving through an RFID exit portalin near real-time, where such additional data is can be used todetermine a probability that the detection of the tag indicates theft.In another aspect of the technology disclosed herein, solutions aredisclosed wherein the RFID detection system is adapted to alarm based onlogic that appears (to the guard) similar to the logic used in AM EASsystems, thus making it easier for a guard or monitor stationed at thescene to determine if a theft is in progress. In another aspect of theinvention, examples of the technology disclosed herein provide adirective to the guard or human monitor to indicate that a person shouldbe intercepted and questioned before they reach the exit.

These and other features of the present disclosure are discussed indetail below with regard to FIGS. 1-9 .

Referring now to FIG. 1 , there is provided a schematic illustration ofan illustrative system 100 that is useful for understanding the presentsolution. The present solution is described herein in relation to aretail store environment. The present solution is not limited in thisregard, and can be used in other environments. For example, the presentsolution can be used in distribution centers, factories and othercommercial environments. Notably, the present solution can be employedin any environment in which objects and/or items/articles need to belocated and/or tracked.

The system 100 is generally configured to allow (a) improved inventorycounts and surveillance of objects and/or items/articles located withina facility, and (b) improved customer experiences. As shown in FIG. 1 ,system 100 comprises a Retail Store Facility (“RSF”) 128 in whichdisplay equipment 102 ₁-102 _(M) is disposed. The display equipment isprovided for displaying objects (or items/articles) 110 ₁-110 _(N), 116₁-116 _(X) to customers of the retail store. The display equipment caninclude, but is not limited to, shelves, article display cabinets,promotional displays, fixtures, and/or equipment se-curing areas of theRSF 128. The RSF 128 can also include emergency equipment (not shown),checkout counters, and other equipment and fixtures typical for thefacility type. Emergency equipment, checkout counters, video cameras,people counters, and conventional EAS systems are well known in the art,and therefore may not be described at a sufficient level of detailherein for understanding of the claimed invention.

At least one tag reader 120 is provided to assist in counting andtracking locations the articles 110 ₁-110 _(N), 116 ₁-116 _(X) withinthe RSF 128. The tag reader 120 comprises an RFID reader configured toread RFID tags. RFID readers are well known in the art, and thereforewill be described at a sufficient level of detail herein forunderstanding of the claimed invention.

RFID tags 112 ₁-112 _(N), 118 ₁-118 _(X) (hereinafter “112,” generally)are respectively attached or coupled to the articles 110 ₁-110 _(N), 116₁-116 _(X) (hereinafter “110,” generally). This coupling can be achievedvia an adhesive (e.g., glue, tape, or sticker), a mechanical coupler(e.g., straps, clamps, snaps, etc.), a weld, chemical bond, or othermeans. The RFID tags 112 can alternatively or additionally comprisedual-technology tags that have both EAS and RFID capabilities asdescribed herein.

Notably, the tag reader 120 is strategically placed at a known locationwithin the RSF 128, for example, at an exit/entrance. By correlating thetag reader's RFID tag reads and the tag reader's known location withinthe RSF 128 it is possible to determine the general location of articles110 within the RSF 128. The tag reader's known coverage area alsofacilitates article 110 location determinations. Accordingly, RFID tagread information and tag reader 120 location information is stored in adatastore 126. This information can be stored in the datastore 126 usinga server 124 and network 144 (e.g., an Intranet and/or Internet).

System 100 also comprises a Mobile Communication Device (“MCD”) 130. MCD130 includes, but is not limited to, a cell phone, a smart phone, atable computer, a personal digital assistant, and/or a wearable device(e.g., a smart watch). Each of the listed devices is well known in theart, and therefore will not be described herein. In accordance with someexamples, the MCD 130 has a software application installed thereon thatis operative to: facilitate the provision of various information 134-142to the individual 152; facilitate a purchase transaction; and/orfacilitate the detachment of the RFID tags 112 from the articles 110;and/or facilitate the detachment of an anchored chain or cable from thearticles 110.

The MCD 130 is generally configured to provide a visual and/or auditoryoutput of item/article level information 134, accessory information 136,related product information 138, discount information 140, and/orcustomer related information 142. The item level information includes,but is not limited to, an item description, item nutritionalinformation, a promotional message, an item regular price, an item saleprice, a currency symbol, and/or a source of the item.

An accessory includes, but is not limited to, a useful auxiliary itemthat can be attached to or removed from an item/article (e.g., a drillbit or battery of a drill). The accessory information includes, but isnot limited to, an accessory description, accessory nutritionalinformation, a promotional message, an accessory regular price, anaccessory sale price, a currency symbol, a source of the accessory,and/or an accessory location in the facility.

A related product includes, but is not limited to, a product/articlethat can be used in conjunction with or as an alternative to anotherproduct/article (e.g., diaper rash cream which can be used when changinga diaper, or a first diaper can be used as an alternative to anotherdiaper). The related product information includes, but is not limitedto, a related product description, related product nutritionalinformation, a promotional message, a related product regular price, arelated product sale price, a currency symbol, a source of the relatedproduct, and/or a related product location in the facility.

The discount information can include, but is not limited to, a discountprice for an article/product based on a loyalty level or other criteria.The customer related information includes, but is not limited to,customer account numbers, customer identifiers, usernames, passwords,payment information, loyalty levels, historical purchase information,and/or activity trends.

The item level information, accessory information, related productinformation and/or discount information can be output in a formatselected from a plurality of formats based on a geographic location ofthe item/article 110, a location of the MCD, a date, and/or an itempricing status (i.e., whether the item/article is on sale). In a displaycontext, the format is defined by a font parameter, a color parameter, abrightness parameter, and/or a display blinking parameter. In anauditory context, the format is defined by a volume parameter, a voicetone parameter, and/or a male/female voice selected parameter.

The MCD 130 can also be configured to read barcodes and/or RFID tags112. Information obtained from the barcode and/or RFID tag reads may becommunicated from the MCD 130 to the server 124 via network 144.Similarly, the stored information 134-142 is provided from the server124 to the MCD 130 via network 144. The network 144 includes an Intranetand/or the Internet.

Server 124 can be local to the facility 128 as shown in FIG. 1 or remotefrom the facility 128. Server 124 will be described in more detail belowin relation to FIG. 4 . Still, it should be understood that server 124is configured to: write data to and read data from datastore 126, RFIDtags 112, and/or MCD 130; perform language and currency conversionoperations using item level information and/or accessory informationobtained from the datastore, RFID tags 112, and/or MCD; perform dataanalytics based on inventory information, tag read information, MCDtracking information, and/or information 134-142; perform imageprocessing using images captured by camera(s) 148; and/or determinelocations of RFID tags 112 and/or MCDs in the RSF 128 using beacon(s)146, tag reader 120 or other devices having known locations and/orantenna patterns.

In some examples, one or more beacons 146 transmitting an RF signal(second RF signal that is non-RFID) other than the RFID interrogationsignal are placed to cover a zone of interest also covered by a tagreader 120 placed to cover an RFID interrogation zone, e.g., at a portalof the retail facility 128. The system 100 can detect and derive anynumber of relevant indicators based on second RF signal. The tag 112response to the second RF signal is analyzed and compared to datacollected by the RFID signal response that occurred concurrently withtag 112 passage through the portal.

The server 124 facilitates updates to the information 134-142 outputfrom the MCD 130. Such information updating can be performedperiodically, in response to instructions received from an associate(e.g., a retail store employee 132), in response to a detected change inthe item level, accessory and/or related product information, inresponse to a detection that an individual is in proximity to an RFIDtag 112, and/or in response to any motion or movement of the RFID tag112. For example, if a certain product/article is placed on sale, thenthe sale price for that product/article is transmitted to MCD 130 vianetwork 144 and/or RFID tag 112. The sale price is then output from theMCD 130. The present solution is not limited to the particulars of thisexample.

Although a single MCD 130 and/or a single server 124 are shown in FIG. 1, the present solution is not limited in this regard. It is contemplatedthat more than one computing device can be implemented. In addition, thepresent solution is not limited to the illustrative system architecturede-scribed in relation to FIG. 1 .

During operation of system 100, the content displayed on the displayscreen of the MCD 130 is dynamically controlled based upon various tag112 or item 110 related information and/or customer related information(e.g., mobile device identifier, mobile device 130 location in RSF 128,and/or customer loyalty level). Tag 112 or item level informationincludes, but is not limited to, first information indicating that anRFID tag 112 is in motion or that an article 110 is being handled by anindividual 152, second information indicating a current location of theRFID tag 112 and/or the MCD 130, third information indicating anaccessory or related product of the article 110 to which the moving RFIDtag 112 is coupled, and/or fourth information indicating the relativelocations of the accessory and the moving RFID tag 112 and/or therelative locations of the related article 110 and the moving RFID tag112. The first, second and fourth information can be derived based onsensor data generated by sensors local to the RFID tag 112. Accordingly,the RFID tags 112 include one or more sensors to detect their currentlocations, detect any individual in proximity thereto, and/or detect anymotion or movement thereof. The sensors include, but are not limited to,an Inertial Measurement Unit (“IMU”), a vibration sensor, a lightsensor, an accelerometer, a gyroscope, a proximity sensor, a microphone,and/or a beacon communication device. The third information can bestored local to the RFID tags 112 or in a remote datastore 126 asinformation 136, 138.

In some scenarios, the MCD 130 facilitates the server's 124 (a)detection of when the individual 152 enters the RSF 128, (b) tracking ofthe individual's movement through the RSF, (c) detection of when theindividual is in proximity to an article 110 to which an RFID tag 112 iscoupled, (d) determination that an RFID tag 112 is being handled ormoved by the individual 152 based on a time stamped pattern of MCDmovement and a timestamped pattern of RFID tag 112 movement, and/or (e)determination of an association of moving RFID tags 112 and theindividual 152.

When a detection is made that an RFID tag 112 is being moved, the server124 can, in some scenarios, obtain customer related information (such asa loyalty level) 142 associated with the individual. This informationcan be obtained from the individual's MCD 130 and/or the datastore 126.The customer related information 142 is then used to retrieve discountinformation 140 for the article 110 to which the RFID tag 112 iscoupled. The retrieved discount information is then communicated fromthe server 124 to the individual's MCD 130. The individual's MCD 130 canoutput the discount information in a visual format and/or an auditoryformat. Other information may also be communicated from the server 124to the individual's MCD 130. The other information includes, but is notlimited to, item level information, accessory information, and/orrelated product information.

In those or other scenarios, a sensor embedded in the RFID tag 112detects when an individual is handling the article 110 to which the RFIDtag 112 is coupled. When such a detection is made, the RFID tag 112retrieves the object's unique identifier from its local memory, andwirelessly communicates the same to the tag reader 120. The tag reader120 then passes the information to the server 124. The server 124 usesthe object's unique identifier and the item/accessory relationshipinformation (e.g., table) 136 to determine if there are any accessoriesassociated therewith. If no accessories exist for the article 110, theserver 124 uses the item level information 134 to determine one or morecharacteristics of the article 110. For example, the article 110includes a product of a specific brand. The server 124 then uses theitem/related product information (e.g., table) 138 to identify: otherproducts of the same type with the same characteristics; and/or otherproducts that are typically used in conjunction with the object. Relatedproduct information for the identified related products is thenretrieved and provided to the MCD 130. The MCD 130 can output therelated product information in a visual format and/or an auditoryformat. The individual 152 can perform user-software interactions withthe MCD 130 to obtain further information obtain the related product ofinterest. The present solution is not limited to the particulars of thisscenario.

Referring now to FIG. 2 , there is an illustration of an illustrativearchitecture for a tag 200. RFID tags 112 ₁-112 _(N), 118 ₁-118 _(X) arethe same as or similar to tag 200. As such, the discussion of tag 200 issufficient for understanding the RFID tags 112 ₁-112 _(N), 118 ₁-118_(X) of FIG. 1 . Tag 200 is generally configured to perform operationsto (a) minimize power usage so as to extend a power source's life (e.g.,a battery or a capacitor), (b) minimize collisions with other tags sothat the tag of interest can be seen at given times, (c) optimize usefulinformation within an inventory system (e.g., communicate useful changeinformation to a tag reader), and/or (d) optimize local featurefunctions.

The tag 200 can include more or less components than that shown in FIG.2 . However, the components shown are sufficient to disclose anillustrative embodiment implementing the present solution. Some or allof the components of the tag 200 can be implemented in hardware,software and/or a combination of hardware and software. The hardwareincludes, but is not limited to, one or more electronic circuits. Theelectronic circuit(s) may comprise passive components (e.g., capacitorsand resistors) and active components (e.g., processors) arranged and/orprogrammed to implement the methods disclosed herein.

The hardware architecture of FIG. 2 represents a representative tag 200configured to facilitate improved inventory management/surveillance andcustomer experience. In this regard, the tag 200 is configured forallowing data to be exchanged with an external device (e.g., tag reader120 of FIG. 1 , a beacon 146 of FIG. 1 , a Mobile Communication Device(“MCD”) 130 of FIG. 1 , and/or server 124 of FIG. 1 ) via wirelesscommunication technology. The wireless communication technology caninclude, but is not limited to, a Radio Frequency Identification(“RFID”) technology, a Near Field Communication (“NFC”) technology,and/or a Short Range Communication (“SRC”) technology. For example, oneor more of the following wireless communication technologies areemployed: Radio Frequency (“RF”) communication technology; Bluetoothtechnology (including Bluetooth Low Energy (LE)); WiFi technology;beacon technology; and/or LiFi technology. Each of the listed wirelesscommunication technologies is well known in the art, and therefore willnot be described in detail herein. Any known or to be known wirelesscommunication technology or other wireless communication technology canbe used herein without limitation.

The components 206-214 shown in FIG. 2 may be collectively referred toherein as a communication enabled device 204, and include a memory 208and a clock/timer 214. Memory 208 may be a volatile memory and/or anon-volatile memory. For example, the memory 208 can include, but is notlimited to, Random Access Memory (“RAM”), Dynamic RAM (“DRAM”), StaticRAM (“SRAM”), Read Only Memory (“ROM”), and flash memory. The memory 208may also comprise unsecure memory and/or secure memory.

In some scenarios, the communication enabled device 204 comprises aSoftware Defined Radio (“SDR”). SDRs are well known in the art, andtherefore will not be described in detail herein. However, it should benoted that the SDR can be programmatically assigned any communicationprotocol that is chosen by a user (e.g., RFID, WiFi, LiFi, Bluetooth,BLE, Nest, ZWave, Zigbee, etc.). The communication protocols are part ofthe device's firmware and reside in memory 208. Notably, thecommunication protocols can be downloaded to the device at any giventime. The initial/default role (being an RFID, WiFi, LiFi, etc. tag) canbe assigned at the deployment thereof. If the user desires to useanother protocol later, the user can remotely change the communicationprotocol of the deployed tag 200. The update of the firmware, in case ofissues, can also be performed remotely.

As shown in FIG. 2 , the communication enabled device 204 comprises atleast one antenna 202, 216 for allowing data to be exchanged with theexternal device via a wireless communication technology (e.g., an RFIDtechnology, an NFC technology, a SRC technology, and/or a beacontechnology). The antenna 202, 216 is configured to receive signals fromthe external device and/or transmit signals generated by thecommunication enabled device 204. The antenna 202, 216 can comprise anear-field or far-field antenna. The antennas include, but are notlimited to, a chip antenna or a loop antenna.

The communication enabled device 204 also comprises a communicationdevice (e.g., a transceiver or transmitter) 206. Communication devices(e.g., transceivers or transmitters) are well known in the art, andtherefore will not be described herein. However, it should be understoodthat the communication device 206 generates and transmits signals (e.g.,RF carrier signals) to external devices, as well as receives signals(e.g., RF signals) transmitted from external devices. In this way, thecommunication enabled device 204 facilitates the registration,identification, and location and/or tracking of an item (e.g., article110 or 112 of FIG. 1 ) to which the tag 200 is coupled.

The communication enabled device 204 is configured so that it:communicates (transmits and receives) in accordance with a time slotcommunication scheme; and selectively enables/disables/bypasses thecommunication device (e.g., transceiver) or at least one communicationsoperation based on output of a motion sensor 250. In some scenarios, thecommunication enabled device 204 selects: one or more time slots from aplurality of time slots based on the tag's unique identifier 224 (e.g.,an Electronic Product Code (“EPC”)); and/or determines a Window Of Time(“WOT”) during which the communication device (e.g., transceiver) 206 isto be turned on or at least one communications operation is be enabledsubsequent to when motion is detected by the motion sensor 250. The WOTcan be determined based on environmental conditions (e.g., humidity,temperature, time of day, relative distance to a location device (e.g.,beacon or location tag), etc.) and/or system conditions (e.g., amount oftraffic, interference occurrences, etc.). In this regard, the tag 200can include additional sensors not shown in FIG. 2 .

The communication enabled device 204 also facilitates the automatic anddynamic modification of item level information 226 that is being or isto be output from the tag 200 in response to certain trigger events. Thetrigger events can include, but are not limited to, the tag's arrival ata particular facility (e.g., RSF 128 of FIG. 1 ), the tag's arrival in aparticular country or geographic region, a date occurrence, a timeoccurrence, a price change, and/or the reception of user instructions.

Item level information 226 and a unique identifier (“ID”) 224 for thetag 200 can be stored in memory 208 of the communication enabled device204 and/or communicated to other external devices (e.g., tag reader 120of FIG. 1 or tag reader 300 of FIG. 3 described below, beacon 146 ofFIG. 1 , MCD 130 of FIG. 1 , and/or server 124 of FIG. 1 ) viacommunication device (e.g., transceiver) 206 and/or interface 240 (e.g.,an Internet Protocol or cellular network interface). For example, thecommunication enabled device 204 can communicate information specifyinga timestamp, a unique identifier for an item/article 110, itemdescription, item price, a currency symbol and/or location informationto an external device. The external device (e.g., server 124, 400 or MCD130) can then store the information in a database (e.g., database 126 ofFIG. 1 ) and/or use the information for various purposes.

The communication enabled device 204 also comprises a controller 210(e.g., a CPU) and in-put/output devices 212. The controller 210 canexecute instructions 222 implementing methods for facilitating inventorycounts and management. In this regard, the controller 210 includes aprocessor (or logic circuitry that responds to instructions) and thememory 208 includes a computer-readable storage medium on which isstored one or more sets of instructions 222 (e.g., software code)configured to implement one or more of the methodologies, procedures, orfunctions described herein. The instructions 222 can also reside,completely or at least partially, with-in the controller 210 duringexecution thereof by the tag 200. The memory 208 and the controller 210also can constitute machine-readable media. The term “machine-readablemedia,” as used here, refers to a single medium or multiple media (e.g.,a centralized or distributed database, and/or associated caches andservers) that store the one or more sets of instructions 222. The term“machine-readable media,” as used here, also refers to any medium thatis capable of storing, encoding, or carrying a set of instructions 222for execution by the tag 200 and that cause the tag 200 to perform anyone or more of the methodologies of the present disclosure.

The input/output devices 212 can include, but are not limited to, adisplay (e.g., an E Ink display, an LCD display, and/or an active matrixdisplay), a speaker, a keypad, and/or light emitting diodes. The displayis used to present item level information in a textual format and/orgraphical format. Similarly, the speaker may be used to output itemlevel information in an auditory format. The speaker and/or lightemitting diodes may be used to output alerts for drawing a person'sattention to the tag 200 (e.g., when motion thereof has been detected)and/or for notifying the person of a particular pricing status (e.g., onsale status) of the item/article 110 to which the tag is coupled.

The clock/timer 214 is configured to determine a date, a time, and/or anexpiration of a pre-defined period of time. Technique for determiningthese listed items are well known in the art, and therefore will not bedescribed herein. Any known or to be known technique for determiningthese listed items can be used herein without limitation.

The tag 200 also comprises an optional location module 230. The locationmodule 230 is generally configured to determine the geographic locationof the tag at any given time. For example, in some scenarios, thelocation module 230 employs Global Positioning System (“GPS”) technologyand/or Internet based local time acquisition technology. The presentsolution is not limited to the particulars of this example. Any known orto be known technique for determining a geographic location can be usedherein without limitation including relative positioning within afacility or structure.

The optional coupler 242 is provided to couple the tag 200 securely orremovably to an item (e.g., object 110 or 112 of FIG. 1 ). The coupler242 includes, but is not limited to, a mechanical coupling means (e.g.,a strap, clip, clamp, snap) and/or adhesive (e.g., glue or sticker). Thecoupler 242 is optional since the coupling can be achieved via a weldand/or chemical bond.

The tag 200 can also include a power source 236, an optional EAScomponent 244, and/or a passive/active/semi-passive RFID component 246.Each of the listed components 236, 244, 246 is well known in the art,and therefore will not be described herein. Any known or to be knownbattery, EAS component and/or RFID component can be used herein withoutlimitation. The power source 236 can include, but is not limited to, arechargeable battery and/or a capacitor.

As shown in FIG. 2 , the tag 200 further comprises an energy harvestingcircuit 232 and a power management circuit 234 for ensuring continuousoperation of the tag 200 without the need to change the rechargeablepower source (e.g., a battery). In some scenarios, the energy harvestingcircuit 232 is configured to harvest energy from one or more sources(e.g., heat, light, vibration, magnetic field, and/or RF energy) and togenerate a relatively low amount of output power from the harvestedenergy. By employing multiple sources for harvesting, the device 200 cancontinue to charge despite the depletion of a source of energy. Energyharvesting circuits are well known in the art, and therefore will not bedescribed herein. Any known or to be known energy harvesting circuit 232can be used herein without limitation.

As noted above, the tag 200 may also include a motion sensor 250. Motionsensors are well known in the art, and therefore will not be describedherein. Any known or to be known motion sensor can be used hereinwithout limitation. For example, the motion sensor 250 includes, but isnot limited to, a vibration sensor, an accelerometer, a gyroscope, alinear motion sensor, a Passive Infrared (“PIR”) sensor, a tilt sensor,and/or a rotation sensor.

The motion sensor 250 is communicatively coupled to the controller 210such that it can notify the controller 210 when tag motion is detected.The motion sensor 250 also communicates sensor data to the controller210. The sensor data is processed by the controller 210 to determinewhether the motion is of a type for triggering enablement of thecommunication device (e.g., transceiver) 206 or at least onecommunications operation. For example, the sensor data can be comparedto stored motion/gesture data 228 to determine if a match existsthere-between. More specifically, a motion/gesture pattern specified bythe sensor data can be compared to a plurality of motion/gesturepatterns specified by the stored motion/gesture data 228. The pluralityof motion/gesture patterns can include, but are not limited to, a motionpattern for walking, a motion pattern for running, a motion pattern forvehicle transport, a motion pattern for vibration caused by equipment ormachinery in proximity to the tag (e.g., an air conditioner or fan), agesture for requesting assistance, a gesture for obtaining additionalproduct information, and/or a gesture for product purchase. The type ofmovement (e.g., vibration or being carried) is then determined based onwhich stored motion/gesture data matches the sensor data. This featureallows the tag 200 to selectively enable the communication device (e.g.,transceiver) or at least one communications operation only when thetag's location within a facility is actually being changed (e.g., andnot when a fan is causing the tag to simply vibrate).

In some scenarios, the tag 200 can be also configured to enter a sleepstate in which at least the motion sensor triggering of communicationoperations is disabled. This is desirable, for example, in scenarioswhen the tag 200 is being shipped or transported from a distributor to acustomer. In those or other scenarios, the tag 200 can be furtherconfigured to enter the sleep state in response to its continuousdetection of motion for a given period of time. The tag 200 transitionfrom a sleep state in response to expiration of a defined time period,tag 200 reception of a control signal from an external device, and/ortag 200 detection of no motion for a period of time.

The power management circuit 234 is generally configured to control thesupply of power to components of the tag 200. In the event all of thestorage and harvesting resources deplete to a point where the tag 200 isabout to enter a shutdown/brownout state, the power management circuit234 can cause an alert to be sent from the tag 200 to a remote device(e.g., tag reader 120 or server 124 of FIG. 1 ). In response to thealert, the remote device can inform an associate (e.g., a store employee132 of FIG. 1 ) so that (s)he can investigate why the tag 200 is notrecharging and/or holding charge.

The power management circuit 234 is also capable of redirecting anenergy source to the tag 200 electronics based on the energy source'sstatus. For example, if harvested energy is sufficient to run the tag200 functions, the power management circuit 234 confirms that all of thetag 200 storage sources are fully charged such that the tag 200electronic components can be run directly from the harvested energy.This ensures that the tag 200 has stored energy in case harvestingsource(s) disappear or lesser energy is harvested for reasons such asdrop in RF, light or vibration power levels. If a sudden drop in any ofthe energy sources is detected, the power management circuit 234 cancause an alert condition to be sent from the tag 200 to the remotedevice (e.g., tag reader 120 or server 124 of FIG. 1 ). At this point,an investigation may be required as to what caused this alarm.Accordingly, the remote device can inform the associate (e.g., a storeemployee 132 of FIG. 1 ) so that (s)he can investigate the issue. It maybe that other merchandise are obscuring the harvesting source or thetagged article 110 is being stolen.

The present solution is not limited to that shown in FIG. 2 . The tag200 can have any architecture provided that it can perform the functionsand operations described herein. For example, all of the componentsshown in FIG. 2 can comprise a single device (e.g., an IntegratedCircuit (“IC”)). Alternatively, some of the components can comprise afirst tag element (e.g., a Commercial Off The Shelf (“COTS”) tag) whilethe remaining components comprise a second tag element communicativelycoupled to the first tag element. The second tag element can provideauxiliary functions (e.g., motion sensing, etc.) to the first tagelement. The second tag element may also control operational states ofthe first tag element. For example, the second tag element canselectively (a) enable and disable one or more features/operations ofthe first tag element (e.g., transceiver operations), (b) couple ordecouple an antenna to and from the first tag element, (c) by-pass atleast one communications device or operation, and/or (d) cause anoperational state of the first tag element to be changed (e.g., causetransitioning the first tag element between a power save mode andnon-power save mode). In some scenarios, the operational state changecan be achieved by changing the binary value of at least one state bit(e.g., from 0 to 1, or vice versa) for causing certain communicationcontrol operations to be performed by the tag 200. Additionally oralternatively, a switch can be actuated for creating a closed or opencircuit. The pre-sent solution is not limited in this regard.

Referring now to FIG. 3 , there is provided a detailed block diagram ofan exemplary architecture for a tag reader 300. Tag reader 120 of FIG. 1is the same as or similar to tag reader 300. As such, the discussion oftag reader 300 is sufficient for understanding tag reader 120.

Tag reader 300 may include more or less components than that shown inFIG. 3 . However, the components shown are sufficient to disclose anillustrative embodiment implementing the present solution. Some or allof the components of the tag reader 300 can be implemented in hardware,software and/or a combination of hardware and software. The hardwareincludes, but is not limited to, one or more electronic circuits. Theelectronic circuit may comprise passive components (e.g., capacitors andresistors) and active components (e.g., processors) arranged and/orprogrammed to implement the methods disclosed herein.

The hardware architecture of FIG. 3 represents an illustration of arepresentative tag reader 300 configured to facilitate improvedinventory counts and management within an RSF (e.g., RSF 128 of FIG. 1). In this regard, the tag reader 300 comprises an RF enabled device 350for allowing data to be exchanged with an external device (e.g., RFIDtags 112 ₁-112 _(N), 118 ₁-118 _(X) of FIG. 1 ) via RF technology. Thecomponents 304-316 shown in FIG. 3 may be collectively referred toherein as the RF enabled device 350, and may include a power source 312(e.g., a battery) or be connected to an external power source (e.g., anAC mains).

The RF enabled device 350 comprises one or more antennas 302 forallowing data to be exchanged with the external device via RF technology(e.g., RFID technology or other RF based technology). The externaldevice may comprise RFID tags 112 ₁-112 _(N), 118 ₁-118 _(X) of FIG. 1 .In this case, the antenna 302 is configured to transmit RF carriersignals (e.g., interrogation signals) to the listed external devices,and/or transmit data response signals (e.g., authentication replysignals or an RFID response signal) generated by the RF enabled device350. In this regard, the RF enabled device 350 comprises an RFtransceiver 308. RF transceivers are well known in the art, andtherefore will not be described herein. However, it should be understoodthat the RF transceiver 308 receives RF signals including informationfrom the transmitting device, and forwards the same to a logiccontroller 310 for extracting the information therefrom.

The extracted information can be used to determine the presence,location, and/or type of movement of an RFID tag within a facility(e.g., RSF 128 of FIG. 1 ). Accordingly, the logic controller 310 canstore the extracted information in memory 304, and execute algorithmsusing the extracted information. For example, the logic controller 310can correlate tag reads with beacon reads to determine the location ofthe RFID tags within the facility. The logic controller 310 can alsoperform pattern recognition operations using sensor data received fromRFID tags and comparison operations between recognized patterns andpre-stored patterns. The logic controller 310 can further select a timeslot from a plurality of time slots based on a tag's unique identifier(e.g., an EPC), and communicate information specifying the selected timeslot to the respective RFID tag. The logic controller 310 mayadditionally determine a WOT during which a given RFID tag'scommunication device (e.g., transceiver) or operation(s) is(are) to beturned on when motion is detected thereby, and communicate the same tothe given RFID tag 200. The WOT can be determined based on environmentalconditions (e.g., temperature, time of day, etc.) and/or systemconditions (e.g., amount of traffic, interference occurrences, etc.).Other operations performed by the logic controller 310 will be apparentfrom the following discussion.

Notably, memory 304 may be a volatile memory and/or a non-volatilememory. For example, the memory 304 can include, but is not limited to,a RAM, a DRAM, an SRAM, a ROM, and a flash memory. The memory 304 mayalso comprise unsecure memory and/or secure memory. The phrase “unsecurememory,” as used herein, refers to memory configured to store data in aplain text form. The phrase “secure memory,” as used herein, refers tomemory configured to store data in an encrypted form and/or memoryhaving or being disposed in a secure or tamper-proof enclosure.

Instructions 322 are stored in memory for execution by the RF enableddevice 350 and that cause the RF enabled device 350 to perform any oneor more of the methodologies of the present disclosure. The instructions322 are generally operative to facilitate determinations as to whetheror not RFID tags 200 are present within a facility 128, where the RFIDtags 200 are located within a facility 128, which RFID tags 200 are inmotion at any given time. Other functions of the RF enabled device 350will become apparent as the discussion progresses.

Referring now to FIG. 4 , there is provided a detailed block diagram ofan exemplary architecture for a server 400. Server 124 of FIG. 1 is thesame as or substantially similar to server 400. As such, the followingdiscussion of server 400 is sufficient for understanding server 124.

Notably, the server 400 may include more or less components than thoseshown in FIG. 4 . However, the components shown are sufficient todisclose an illustrative embodiment implementing the present solution.The hardware architecture of FIG. 4 represents one embodiment of arepresentative server configured to facilitate inventory counts,inventory management, and improved customer experiences.

Some or all the components of the server 400 can be implemented ashardware, software and/or a combination of hardware and software. Thehardware includes, but is not limited to, one or more electroniccircuits. The electronic circuits can include, but are not limited to,passive components (e.g., resistors and capacitors) and/or activecomponents (e.g., amplifiers and/or microprocessors). The passive and/oractive components can be adapted to, arranged to, and/or programmed toperform one or more of the methodologies, procedures, or functionsdescribed herein.

As shown in FIG. 4 , the server 400 comprises a user interface 402, aCPU 406, a system bus 410, a memory 412 connected to and accessible byother portions of server 400 through system bus 410, and hardwareentities 414 connected to system bus 410. The user interface can includeinput devices (e.g., a keypad 450) and output devices (e.g., speaker452, a display 454, and/or light emitting diodes 456), which facilitateuser-software interactions for controlling operations of the server 400.

At least some of the hardware entities 414 perform actions involvingaccess to and use of memory 412, which can be a RAM, a disk driver,and/or a Compact Disc Read Only Memory (“CD-ROM”). Hardware entities 414can include a disk drive unit 416 comprising a computer-readable storagemedium 418 on which is stored one or more sets of instructions 420(e.g., software code) configured to implement one or more of themethodologies, procedures, or functions described herein. Theinstructions 420 can also reside, completely or at least partially,with-in the memory 412 and/or within the CPU 406 during executionthereof by the server 400. The memory 412 and the CPU 406 also canconstitute machine-readable media. The term “machine-readable media,” asused here, refers to a single medium or multiple media (e.g., acentralized or distributed database, and/or associated caches andservers) that store the one or more sets of instructions 420. The term“machine-readable media,” as used here, also refers to any medium thatis capable of storing, encoding, or carrying a set of instructions 420for execution by the server 400 and that cause the server 400 to performany one or more of the methodologies of the present disclosure.

In some scenarios, the hardware entities 414 include an electroniccircuit (e.g., a processor) programmed for facilitating the provision ofa three-dimensional map showing locations of RFID tags 200 within afacility and/or changes to said locations in near real-time. In thisregard, it should be understood that the electronic circuit can accessand run a software application 422 installed on the server 400. Thesoftware application 422 is generally operative to facilitate thedetermination of RFID tag 200 locations within a facility, the directionof travel of RFID tags 200 in motion, and the mapping of the RFID tag200 locations and movements in a virtual three-dimensional space.

In those or other scenarios, the hardware entities 414 include anelectronic circuit (e.g., a processor) programmed for facilitatingitem/article inventorying, merchandise sale, and/or customersatisfaction with a shopping experience. In this regard, the electroniccircuit can access and run an inventorying software application 422 andan MCD display software application 422 installed on the server 400. Thesoftware applications 422 are collectively generally operative to:obtain item level information and/or other information from MCDs andRFID tags 200; program item level information, accessory information,related product information and/or discount information onto RFID tags200 and/or MCDs; convert the language, pricing and/or currency symbol ofitem level information, accessory information, related productinformation and/or discount information; facilitate registration of RFIDtags 200 and MCDs with an enterprise system; and/or determine when MCDdisplay update actions need to be taken based on RFID tag 200information. Other functions of the software applications 422 willbecome apparent as the discussion progresses. Such other functions canrelate to tag reader control and/or tag control.

In FIGS. 5-7 there is shown an RFID portal 500 (plan view in FIG. 5 ,top view in FIG. 6 ), which is useful for understanding certain aspectsof the technology disclosed herein. The RFID portal 500 includes twoRFID readers 506 a, 506 b (such as tag reader 300, hereinafter “506,”generally); each of them are respectively attached to antennas 502 a,502 b (such as antenna 302, hereinafter “502,” generally) mounted onsides of the portal 500. An RFID reader 506 as referenced herein iscapable of generating RFID tag exciter signals to control and elicitresponses from one or more of a plurality of RFID tags 510 (such as tag200) in a RFID portal zone. The RFID exciter signals can also serve as asource of power for energizing the RFID tags 510. The exciter signalsgenerated by the RFID readers 506 and responses received by each reader506 will be in accordance with an RFID system standard that is now knownor known in the future. The RFID readers 506 also can detect, identify,and/or process one or more the responses from the plurality of RFID tags510 in a portal zone. The RFID readers 506 include suitable interfacecircuitry to facilitate communications with a system controller 508(such as server 400) as described below. For example, the interfacecircuitry can facilitate communication of information regarding detectedresponses received from RFID tags 510. Such interface circuitry can alsofacilitate reception of interrogation commands and/or antenna beamcontrol commands from the system controller 508.

In the portal 500 shown, the antennas 502 are mounted on pedestals 503a, 503 b (hereinafter “503,” generally), but the technology disclosedherein is not limited in this regard. Antennas 502 can be mounted in theceiling or in the ground, and the method described herein would still beapplicable. There is no restriction regarding the type of antennas 502that are used to produce the required field patterns. However, in thisexample portal 500, antennas 502 are understood to be beam steerable sothat multiple different antenna beam directions can be obtained from asingle antenna 502. Control over the required antenna field patterns canbe facilitated by the RFID readers 506 as noted above. In addition, twoantennas, 502 a and 502 b, are shown in FIG. 5 , but it should beunderstood that the technology disclosed herein is not limited in thisregard. The inventive arrangements descried herein could be implementedusing a single beam steerable antenna.

The RFID portal 500 can be placed in the vicinity of an exit point in afacility where articles 110 must pass through in order to transitionfrom one space inside the facility 128 to a second space, which isoutside of the facility 128. In the example shown in FIG. 5 and FIG. 6 ,the exit point is a doorway 504, but the technology disclosed herein isnot limited in this regard. The exit/choke point can also be a wide exitsuch as those seen in shopping malls, which is open to another interiorspace, which is not a part of the facility 128. The RFID readers 506 canbe operated under the command of a system controller 508, such as server124, which facilitates the detection of one or more RFID tags 510 withina field of view of each antenna 502 as hereinafter described.

In the arrangement shown in FIG. 5 and FIG. 6 , a human guard or monitorwill likely be stationed near the RFID portal 500 to observe andinteract with shoppers exiting the retail store 128. Referring now toFIG. 7 , a representation 700 of a human guard or monitor 702(hereinafter “guard 702”) is shown in proximity of the RFID portal 500.The guard 702 has one or more personal communication devices on theirperson, such as the device 130. The device 130 enables one or morenetworked systems such as the network 144 to communicate with the guard702 via the device 130. Near-real time communications that may berelevant to the detection of unauthorized RFID tags 510 by the system500 are sent to the device 130. “Unauthorized RFID tags” are detectedtags 510 where the tag data does not confirm that the article to whichthe tag 510 was attached was purchased prior to reaching the RFID portal500. In some examples, when an unauthorized RFID tag 510 is detected, analarm event flag is set. If the alarm event flag is validated, ahuman-perceptible alarm is triggered. If the alarm event flag is notvalidated, it is assumed to be a false alarm, and the alarm event flagis cleared.

In some examples, the device 130 carried by the guard 702 is enabled forbidirectional voice-data communication, and includes a display, memory,and a processor. The device 130 can be a smart phone having anapplication running thereon, or otherwise it can a dedicated proprietarydevice 130. The device 130 can display additional information useful tothe guard 702 relating to the detected tag 510 to enable the guard 702to make accurate decisions quickly as to whether to detain people basedon suspected theft of an article 110.

In some examples, additional related data can be collected by measuringthe reflected energy, e.g., using a received signal strength indicator(RSSI) or a received channel power indicator (RCPI), from a detectedRFID tag 510. The RSSI can then be used as an estimate of the distanceof the tag 510 from the interrogating antenna 502. Based on testing andexperimentation, a typical RF power at the antenna is 1 W conducted and3-6 dB of antenna gain. This is considered to be a very large signalstrength. Therefore, the reflected energy (RSSI) from a RFID tag is alsovery large. For most tags 510 and systems running at high power, thereflected energy will be −50 dBm to −0 dBm.

The transmitted signal strength typically drops off by 24-34 dB in thefirst meter of separation from the antenna 502. Thereafter, the signalstrength typically falls off 6 dB for every doubling of the distanceaway from the antenna 502. At two meters away, the signal strength isdown 6 dB, at four meters away it is down 12 dB, at eight meters away itis down 18 dB, etc. Therefore, if a person is within 1-2 feet of theface of the antenna 502 and proceeds to move a detectable tag 510 backand forth, then the RSSI value for the tag read should exceed anypossible RSSI for a tag 510 greater than 4 feet away. These numbers arefor illustration purposed only, and in practice, it may be necessary toadjust the values based on the frequency of the specific portal 500. Therules and regulations for RFID transmissions vary by country andjurisdiction, resulting in the use of different frequencies andtransmission strengths in different RFID portals 500. The values alsomay be adjusted depending on the type and manufacturer of the RFID tags510 on the products/garments.

One problem encountered at times with RFID portal 500 alarm detection isthat the customers do not typically walk within one foot if the RFIDantennas 502. Also, in many RFID portals, a more complex algorithm canbe used that reads into and out of the store 128 by beam steering theRFID read signals into and out of the store 128. Such a system isdescribed in U.S. Pat. No. 9,519,811 entitled “SYSTEM AND METHOD FORREADING RFID TAGS ACROSS A PORTAL,” which is commonly owned with thepresent application (hereinafter “the '811 patent”). The contents of the'811 patent are hereby incorporated herein.

As described in the '811 patent, RFID tag 510 interrogation can involveinterrogating tags 510 using the dual-target mode in one of the latchedsessions S1, S2 or S3. In the dual-target mode, each of the tags 510will be read continuously regardless of whether the tag is in state “A”or state “B.” The expectation in such scenarios is to be able to readall tags 510 within the field of view (FOV) of the reader antenna 502,regardless of the inventoried flag state. Typically, the power level ofthe RFID electromagnetic exciter field is manually tuned to limit thereading of static tags that might be far from the RFID reader 506. Butas more time is spent by an RFID reader 506 to inventory the tags in theFOV of its steerable antenna 602, the opportunities increase to miss atag 510 that is crossing in an area that is not then covered by theantenna beam. This problem can become particularly noteworthy when manytags 510 are present. It also detracts from the ability of the portal500 to focus attention on the tags 510 that are actually crossingthrough the portal (as opposed to static tags 510 which are not inmotion).

The system described in the '811 patent includes executing a combinationof RFID tag reads using different sessions, power levels, and beamdirections so as to improve RFID portal 500 accuracy in a dense tagpopulation. The combination of read cycles allows an RFID portal 500 todetect the surrounding tags 510 and focus on the crossings tags 510. Butbecause there potentially are a lot of tags 510 that can be read insidethe store 128, the detection algorithms use session information and RSSIchange information that requires multiple reads over time. As a result,if the guard 702 at the RFID portal 500 walks the bag with potentiallystolen articles 110 back through the RFID portal 500, then tags 510therein have a very low probability of alarming again.

A problem that is prevalent in the industry is that store personnel,especially human exit guards such as guard 702, expect the RFID portal500 alarm to work in the same way as acousto-magnetic (AM) EAS systemsthat they may have become accustomed to working with.

Examples of the technology disclosed herein include offering some alarmdetection logic similar to that of an AM EAS system. In some examples,the RFID portal 500 alarms when an RFID tag 510 (still attached to thearticle) is placed within a short distance (e.g., under 18″) the RFIDportal 500 antennas 502. While this approach differs slightly from theoperation of an AM system (because the range of where the tags 510 wouldneed to be placed would be much smaller: e.g., 1-2 feet, as opposed to3-7 feet for the AM system), the example methods is useful fordetermining probable theft after an initial alarm event flag is set, andwould help solve some of the problems set forth above.

In addition, consider that RFID tags 510 on the articles 110 each have aserial number and are unique to the article 110 that they are attachedto. Therefore, an Electronic Product Code (EPC) or Stock Keeping Unit(SKU) number can be sent in real-time to am MCM 130 (such as a mobiledevice, tablet, handheld RFID reader), or to a smart screen (e.g., on ornear the RFID portal 500). Then system can then query datastore 126 toobtain data describing the article 110 associated with the detected tag510. The retrieved data can include a description of the article 110,e.g., including, size, color, ID numbers, and price, along with an imagefile of the article 110 associated with the alarming tag 510 that can bedisplayed to the guard 702, e.g., on MCM 130.

The image of the article 110 and associated description may assist theguard 702 in validating the alarm event flag at the RFID portal 500. Theguard 702 may be able to quickly inspect the inside the customer's bagto visually determine if the article in question is inside the bag. Insome examples of the technology disclosed herein, the system 100retrieves data from one or more back end retail theft databases toprovide still more information that the guard could use to determine ifa theft is occurring. Such approaches can support the guard's 702decision in at least two ways: (a) information acquired by the exitsystem logic, this is probability of this event being a theft asdetermined by the exit system and (b) such event combined with a backendsystem where a datastore can provide relevant data pertaining to theft.

In some examples, the data providing enriched information to the guard702 can include: the frequency that the type of article 110 is stolenfrom all stores (e.g., store item stolen ranking), the frequency thatsuch an article 110 is stolen from that particular store (e.g., storeneighborhood stole item ranking), customer information to help determineif this is a known good customer or a previous theft customer,historical information on how often such articles 110 are being stolenand during what time of day, the total count of articles 110 beingstolen, and other relevant information.

The customer information can be obtained using any number of well-knownmethods. Cameras can be used to capture facial image data of thesuspected thief, and the system can use facial recognition algorithms tocompare this image with images in a database of known shoplifters. Thecustomer's identity may be tracked from the point of sale (POS) wherethe customer used a credit or debit card, or a loyalty card associatedwith the customer. The identified customer can then be tracked to thepoint of exit using any suitable human tracking system. The customer canalso be identified by responses from their mobile devices, and loyaltycards they may be carrying. For example, the customer may be logged intothe store's Wi-Fi, or may be using running the store's application ontheir phone. It is not necessary to obtain the real legal identity ofthe customer. The identity data sensed from the customer and/or theirphone can be compared on an anonymous basis with similar data in a knownthief database.

A theft probability algorithm can assign weights to the various dataparameters retrieved from a theft database. Some examples of thetechnology disclosed herein can use the theft probability algorithm todetermine a percentage representing an estimated overall probability oftheft relating to the alarm event flag. This probability of theft can bebased at least in part on analysis of local data collected at the scene,in combination with historical and statistical data retrieved from thetheft database.

The calculated probability of theft, represented as a percentage, can betransmitted to the guard via the MCD 130 and displayed thereon. In someexamples, the retrieved data from the theft database can be displayed onthe MCD 130 in a raw format, so that the guard 702 can view the actualdata and make their own determination as to the probability that theftis occurring. In practice, both the calculated probability percentageand the raw data results can be simultaneously displayed on an MCD 130.

In some examples of the technology disclosed herein, the calculatedprobability of theft can be used to provide an explicit directive to theguard 702 or additional employees that the person attempting to exit thepremises should be stopped and questioned about their purchases andarticles they may be carrying. This can be accomplished by setting athreshold on the calculated probability of theft where the interceptionof the customer is required. Other parameters can be used to instead of,or in addition to, the calculated probability of theft, to determinewhen a customer should definitely be stopped before exiting. Forexample, if the customer is identified as a known, habitual thief, thisfactor alone can trigger a directive to stop the customer if thecustomer is associated with an alarm event flag. The exact parameters tobe used in a determination of when a customer should be stopped can beselected by the retailer.

Sending explicit notifications to one or more employees directing themthat a customer is to be intercepted before exiting can provide manyadvantages. The technology reduces the need for subjective “on the spot”decisions by employees which may take too much time. The technologyhelps guards and other employees to more effectively do their jobsbecause they do not have to second-guess their own decision to stop acustomer. A system-generated directive to stop the customer also savestime, because the window in which a customer can be stopped, between thetime they set off the alarm to the time they exit the store, can be veryshort.

In accordance with some examples of the technology disclosed herein, theguard 702 receives, through device 130, a system-generated message thatthey are to stop a particular customer. The system-generated “stopcustomer” message can be sent to multiple employees are once who may bein proximity of the exits. The notification message to stop the customernecessarily includes sufficient information on the customer to allow theguard to identify, quickly and accurately, the customer to be stopped.The information conveyed to the guard can include the display ofreal-time motion map showing representations of people and objectsmoving toward the exits, where the representation of the person to bestopped is highlighted. Other methods include sending a visual image ofthe person to the guard's mobile device, where the image was taken atthe moment the RFID portal 500 alarmed. In one embodiment, the image canbe taken by a camera mounted on the RFID portal 500.

The guard 703 can also be equipped with a reader 300 that enables theguard 702 to scan a customer's receipt (e.g. using a barcode, QR, OCRetc.) to determine what articles 110 are in the customer's possessioncompared with those articles 110 processed at POS, and in comparisonwith the RFID “license plate,” which is the tag data detected by theRFID portal 500.

The guard 702 could use the additional information communicated to theirdevice 130 to facilitate and improve upon their decisions. For example,if the alarm is on an article 110 that is near the RFID portal 500 andthe guard 702 did not see the customer walk near the RFID portal 500,then the guard 702 can, at their discretion, ignore this alarm eventflag. If the RFID portal 500 has a camera and it can determine that theperson leaving is known to have stolen before, then the guard 702 canstop that person and check their bags. If the guard 702 has a handheldRFID reader 300, then this information can be sent to that device sothat the guard can scan the customers to find the specific RFID tags 510that are being indicated as stolen.

In an example system 100, the RSSI is set to a threshold of 68. Thiscorresponds to a read range of 6 inches at 22 dBm power with a 4-6 dBgain antenna, 9-12 inches at 25 dBm and 12-18 inches at 30 dBm. Thesevalues are approximate and depend on the power settings. In a variation,the power is set to 30 dBm on all of the antennas. It is believed thatthis setting will raise the RSSI threshold to make it harder to triggeran alarm, thus reducing the occurrences of false alarms.

To reduce the risk of multiple signals bouncing constructively into thestore 128 and giving a high power to a tag 200 that is sitting insidethe store, in some examples of the technology disclosed herein, aminimum number of high RSSI reads is required before an alarm event flagis triggered. In practice, minimum number of high RSSI read could be setto 1, but in some cases, it should be set to 2 or 3 read eventsexceeding the threshold within a few seconds.

In some examples of the technology disclosed herein, the alarm eventlogic can also be gated by only triggering an alarm if one of the peoplecounter/motion sensor detectors is triggered. In some examples, where anoverhead people counter is the data source, an alarm is only triggeredwhen a person is standing near the exit gate for a minimum time afterthe detection of an unauthorized tag. In some examples, the alarm logicis based on detecting motion near the pedestal and then determining thata person is within reach of a pedestal, and concurrently getting one ormore high-RSSI reads. In some examples of the technology disclosedherein, if all three of the above criteria are met after an unauthorizedtag 200 is detected, a rule is applied that the alarm is automaticallytriggered.

In the practice of examples of the technology, the value of theparameters to be set are selected based on the individual system, andthe location of that system, so that the technology can be implementedfor all of the different types of RFID tags 200, articles 110, taggingmethods, regulatory regions, and use cases. For example, in the US thereare 50 frequencies used for RFID protocols, and each one will have aslightly different optimal value. In these cases, logic can be added tochange the threshold for each transmission frequency.

Referring to FIG. 8 , and continuing to refer to prior figures forcontext, methods 800 for electronic article surveillance (EAS) areshown. In such methods 800, an RFID portal of an EAS system firstinterrogates in a first zone extending into a controlled area beyond athreshold distance from an interrogating antenna of the RFIDportal—Block 810. In such methods, the RFID portal defines an exit fromthe controlled area, the threshold distance being less than a width ofthe exit.

Consider, as a continuing example, a customer purchasing two articles110 (tagged with tag X 112) and article 116 (tagged with tag Y 118) at aPOS in store 128. The POS updates datastore 126 with the “purchased”status of article 116, authorizing the article 116 to leave the store128, but fails to update the purchase status of article 110, whichremains unauthorized to leave the store.

In the continuing example, RFID portal 500 interrogates in a first zoneextending into the store 128 by executing a combination of RFID tagreads around using different sessions, power levels, and beamdirections, e.g., per the '811 patent. In the continuing example, thefirst interrogation zone at times extends outside the store 128. Thecombination of read cycles allows an RFID portal 500 to detect thesurrounding tags 510 and focus on the tags 510 crossing/about to crossthrough the RFID portal 500. But because there potentially are a lot oftags 510 that can be read inside the store 128, the detection algorithmsuse session information and RSSI change information that requiresmultiple reads over time. As a result, if the guard 702 at the RFIDportal 500 walks a bag with potentially stolen articles 110 (tags 510attached) back through the RFID portal 500, then tags 510 therein have avery low probability of alarming again, i.e., a given tag 510 may not beguaranteed to respond to a subsequent interrogation during themultisession interrogation period. Yet, re-interrogating a bag orarticle is an expected practice of a guard 702. In the continuingexample, the threshold distance is about 1 ft. (corresponding to anexpected drop off of about 10 dB in received power at a tag 510), thepower level of the first interrogation is 1 W (conducted), and with 4 dBof antenna gain in each of two beam steered antennas 502.

Referring to FIG. 9 , in operation, EAS system 100 may perform themethod 800 of electronic article surveillance, by such as via executionof application component 915 by processor 905 and/or memory 910—whereinapplication component 915, processor 905, and/or memory 910 arecomponents of computing device 900. Computing device 900 can be one ormore of a tag 510, a tag reader 506, and system controller 508—asappropriate as explained elsewhere herein. In a separate example,application component 915 includes first interrogating component 925that is configured to or may comprise means for first interrogating in afirst zone extending into a controlled area beyond a threshold distancefrom an interrogating antenna of the RFID portal.

The RFID portal 500 first detects, in response to the firstinterrogating, a first response of a particular RFID tag—Block 820. Inthe continuing example, RFID portal 500 detects Tag X 112 and tag Y 118(about 5 ft. away from one of the antennas 602, inside the store 128),and further determines that tag X 112 is moving in the direction of theexit/RFID portal 500 without authorization to leave the store128—thereby setting an alarm event flag. The EAS system notifies a guard702 stationed near the RFID portal 500, through the guard's handheldmobile communication device 130 (a mobile phone), that an alarm eventflag has been set—though the alarm is not yet sounded—and instructs theguard 702 to check for customers exiting through the RFID portal 500,and to examine articles 110, 116 carried by such customers. The guard702 finds one customer carrying an article 110 still carrying a tag 510and article 116 also still carrying a tag 510. In the separate example,application component 915 includes first detecting component 930 that isconfigured to or may comprise means for first detecting, in response tothe first interrogating, a first response of a particular RFID tag.

Subsequent to the first detecting, the RFID portal second interrogatesin a second zone extending into the controlled area at least to thethreshold distance—Block 830. In the continuing example, the secondinterrogation is in response to the first detecting, and comprisesinterrogating in which all RFID tags 510 in the second interrogationfield are allowed to respond. The same conducted power is used as in thefirst interrogation. In particular, the guard 702, in response to thenotification described above, passes each of the customer-carriedarticle 116 still carrying a tag 510 (also as yet unidentified by theguard 702) and then article 112 still carrying a tag 510 (as yetunidentified by the guard 702) in turn within 1 ft. of an antenna 502 ina pedestal 503 of the RFID portal 500 (inside the threshold distance inthe second interrogation zone) during this second interrogationperiod—in a fashion similar to procedures for AM EAS systems. In theseparate example, application component 915 includes secondinterrogating component 935 that is configured to or may comprise meansfor second interrogating in a second zone extending into the controlledarea at least to the threshold distance.

RFID portal second detects, in response to the second interrogating, atleast one second response of the particular RFID tag indicating areceived signal strength of the second interrogating at the particularRFID tag corresponding to a distance from an interrogating antenna ofthe RFID portal less than the threshold distance—Block 840. In thecontinuing example, the RFID portal 500 detects tag Y 118 multiple timesas the guard 702 passes article 116 with tag Y 118 attached within 1 ft.of antenna 502, but since tag Y 118 was authorized to leave the store128, no action is taken by the EAS system 100. The RFID portal 500 thendetects tag X 510 multiple times as the guard 702 waves the article 110(to which a tag X 112 remains attached) within 1 ft. of an antenna 502of the RFID portal 500. The detected response from tag X 112 bothidentifies the tag 510 as tag X 112 and includes an RSSI correspondingroughly to the expected received signal strength at a tag within 1 ft.of antenna 502. In the separate example, application component 915includes second detecting component 940 that is configured to or maycomprise means for second detecting, in response to the secondinterrogating, at least one second response of the particular RFID tagindicating a received signal strength of the second interrogating at theparticular RFID tag corresponding to a distance from an interrogatingantenna of the RFID portal less than the threshold distance.

The EAS system alarms in response to the second detecting—Block 850. Inthe continuing example, the detection of unauthorized tag X 112 sets ofan alarm at the RFID portal 500, notifying the guard that tag X 112 hasnot been authorized to leave the store 128. In the continuing example,the guard 702 confirms that the POS system failed to record properly thearticle 110 to which tag X 112 was attached as “purchased.” In theseparate example, application component 915 includes alarming component945 that is configured to or may comprise means for alarms in responseto the second detecting.

In some examples, after RFID tag detection is initiated, the EAS system100 determines whether a given tag is authorized for removal. If thegiven tag is not authorized for removal, the EAS system 100 sets analarm event flag and transmits an alarm even flag alert to a mobiledevice 130 of an employee on scene in a store 128 to monitor an RFIDportal 500. The EAS system 100 estimates the location of the given tagbased on RSSI. If the given tag's estimated location is within athreshold distance, e.g., 18 in., of an antenna 502 of the RFID portal500, then the EAS system 100 triggers an alarm, transmitting an alarm tothe mobile device 130 of the employee. If the given tag's estimatedlocation is not within a threshold distance, e.g., 18 in., of an antenna502 of the RFID portal 500, then the EAS system 100 collects theftprobability data related to the alarm event.

The collected theft probability data can be sent to the employee throughthe mobile device 130 and sent for analysis on the EAS system 100server. On the server, the EAS system 100 can use real-time peoplecounter/motion sensor data to determine if a person was detected in theRFID portal 500. If no person was detected, the EAS system 100 cancelsthe alarm flag. If a person was detected, then the EAS system determinesif the person was moving. If the detected person was not moving, thenthe EAS system 100 cancels the alarm flag. If the detected person wasfound to be moving, then the EAS system triggers an alarm and transmitsan alarm confirmation alert to the mobile device 130 of the employee atthe RFID portal 500.

In addition, the collected theft probability data can be combined withRFID portal 500 and POS sensors to capture customer-identifying data,which can then be used to query a known thief database 314 for possiblematched. If a match is located, then the EAS system 100 triggers analarm and transmits an alarm confirmation alert to the mobile device 130of the employee at the RFID portal 500. Further, collected theftprobability data can be used to query an enterprise database for productinfo corresponding to the detected RFID tag. The retrieved product infocan be transmitted to the mobile device 130 of the employee at the RFIDportal 500, displaying an image of the alerted item along with a productdescription. Further yet, the collected theft probability data can beused to query the theft database 314 for historical theft data relevantto the article, store location, time and date parameters andcustomer-identifying information. The retrieved information can betransmitted to the mobile device 130 of the employee at the RFID portal500 along with a calculated percentage probability that a theft isoccurring.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “one or more of A, B, or C,” “at least oneof A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or anycombination thereof” include any combination of A, B, and/or C, and mayinclude multiples of A, multiples of B, or multiples of C. Specifically,combinations such as “at least one of A, B, or C,” “one or more of A, B,or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and“A, B, C, or any combination thereof” may be A only, B only, C only, Aand B, A and C, B and C, or A and B and C, where any such combinationsmay contain one or more member or members of A, B, or C. All structuraland functional equivalents to the elements of the various aspectsdescribed throughout this disclosure that are known or later come to beknown to those of ordinary skill in the art are expressly incorporatedherein by reference and are intended to be encompassed by the claims.

Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe claims. The words “module,” “mechanism,” “element,” “device,” andthe like may not be a substitute for the word “means.” As such, no claimelement is to be construed as a means plus function unless the elementis expressly recited using the phrase “means for.”

What is claimed is:
 1. A method of electronic article surveillance (EAS), comprising: first interrogating, by an RFID portal of an EAS system, into a controlled area; first detecting, by the RFID portal and in response to the first interrogating, a first response of a particular RFID tag indicating an alarm event; second interrogating, by the RFID portal and subsequent to the first detecting, into the controlled area; second detecting, by the RFID portal and in response to the second interrogating, at least one second response of the particular RFID tag indicating a received signal strength of the second interrogating at the particular RFID tag corresponding to a distance from an interrogating antenna of the RFID portal less than a threshold distance; and alarming, by the EAS system, in response to the alarm event and the second detecting.
 2. The method of claim 1, wherein: first detecting comprises determining, by the EAS system, that the particular tag is moving in a direction exiting the controlled area, and the second interrogating is in response to the first detecting.
 3. The method of claim 1, wherein alarming comprises displaying information relating to at least one of: the particular RFID tag, and an article associated with the particular RFID tag.
 4. The method of claim 3, displaying comprises displaying on one of the RFID portal or a mobile communication device.
 5. The method of claim 1, wherein indicating a received signal strength comprises responding with a received signal strength indicator (RSSI).
 6. The method of claim 1, wherein the threshold distance is no greater than one foot.
 7. The method of claim 1, wherein the threshold distance is no greater than two feet.
 8. The method of claim 1, further comprising, receiving, by the EAS system prior to the first interrogating, selection of the threshold distance.
 9. The method of claim 1, wherein: the first interrogating comprises multi-session interrogating during which the particular RFID tag would not be guaranteed to respond to a subsequent interrogation; and the second interrogating comprises interrogating in which all RFID tags within the threshold distance are allowed to respond.
 10. The method of claim 1, wherein the second detecting comprises at least a predetermined threshold number, greater than one, of second responses.
 11. The method of claim 1, wherein the alarming further requires an indication of at least one person in the portal concurrent with the first detecting.
 12. A electronic article surveillance (EAS) system, comprising: a radio frequency identification (RFID) portal operative to: first interrogate into a controlled area; first detect, in response to the first interrogating, a first response of a particular RFID tag indicating an alarm event; second interrogate, in response to the first interrogating, a first response of a particular RFID tag indicating an alarm event; second detect, in response to the second interrogating, at least one second response of the particular RFID tag indicating a received signal strength of the second interrogating at the particular RFID tag corresponding to a distance from an interrogating antenna of the RFID portal less than a threshold distance; and alarm, by the EAS system, in response to the alarm event and the second detecting.
 13. The system of claim 12, wherein: first detecting comprises determining, by the EAS system, that the particular tag is moving in a direction exiting the controlled area, and the second interrogating is in response to the first detecting.
 14. The system of claim 12, wherein alarming comprises displaying information relating to at least one of: the particular RFID tag, and an article associated with the particular RFID tag.
 15. The system of claim 14, displaying comprises displaying on one of the RFID portal or a mobile communication device.
 16. The system of claim 12, wherein indicating a received signal strength comprises responding with a received signal strength indicator (RSSI).
 17. The system of claim 12, wherein the threshold distance is no greater than one foot.
 18. The system of claim 12, wherein the threshold distance is no greater than two feet.
 19. The system of claim 12, wherein the RFID portal is further operative to receiving, prior to the first interrogating, selection of the threshold distance.
 20. An apparatus for electronic article surveillance (EAS), comprising: means for first interrogating, by an RFID portal of an EAS system, into a controlled area; means for first detecting, by the RFID portal and in response to the first interrogating, a first response of a particular RFID tag indicating an alarm event; means for second interrogating, by the RFID portal and in response to the first interrogating, a first response of a particular RFID tag indicating an alarm event; means for second detecting, by the RFID portal and in response to the second interrogating, at least one second response of the particular RFID tag indicating a received signal strength of the second interrogating at the particular RFID tag corresponding to a distance from an interrogating antenna of the RFID portal less than a threshold distance; and means for alarming, by the EAS system, in response to the alarm event and the second detecting. 